Reams of nebulae are easily accessible to amateur astronomers but some of them are sometimes more popullar than others.
So, here is a couple of unfamous nebulae, photographed by Nicolas Kizilian : Sharpless Sh2-129 (in red) and Ou4 (in blue).
Located in Cepheus constellation, their size is particularly large with an angular dimension of 2.3° for Sh2-129 and a little more than 1° for Ou4.

Ou4 : a recent discovery

The Ou4 nebula, well-known as the "The Giant Squid Nebula" was discovered in may 2011 by french amateur astronomer Nicolas Outters , an astronomy enthusiast and above all a recognized planetary nebula discoverer !
While photographing the Sharpless nebula, N.Outters noticed a tiny blue cloud, spreading inside this large red nebula. However, Ou4 only appeared using a specific tool mounted in front of the camera's sensor : an OIII filter, whose function is to observe a restricted part of the whole visible spectrum (around 500 nm).
⇒ More details on his incredible discovery here (in french).

A nature that it is still to identify

Although the Sh2-129 neubula is correctly identified as an emission nebula, its host's nature, the Ou4 nebula still needs to be checked. Similarly, what caused its formation and how far it is from us are still unanswered questions.
Nevertheless, some scientists are able to qualify its structure as a bipolar outflow, possibly produced by a triple star system, visible inside Ou4 ...

A real challenge to capture

Nicolas Kizilian, an advanced amateur astrophotographer managed to well-control the recording of these nebulae, which are let is say, extremely faint.
It requires indeed a total exposure of 25h20 ! This though work has been obviously separated on several nights and also required a time organisation : 19h20 for Ou4 using an OIII filter and 6h for Sharpless Sh2-129 using a Ha filter.
Nicolas used a Moravian G2-8300 CCD camera at prime focus of a WO ZenithStar 66 refractor, mounted on a AZ-EQ6.
What a nice work, is not it ?